The present invention relates to a thermal protector, more particularly to a thermal protector suitable for a temperature switch which is activated at a high operating temperature such as over 200° C. and has a relatively large current rating.
There has been known a thermal protector which uses a bimetal element as a thermal responsive element to open and close an electric circuit thereof using an inverting action of the element which occurs at a predetermined temperature. As an example of such a thermal protector, Japanese Patent Publication No. 2844026 discloses a thermal protector including a movable plate which has a movable contact point at a distal end thereof and constituted of a spring material; and a sheet-like thermal responsive element which performs an inverting action and is fixed to a terminal portion of the movable plate. Then, the movable contact point of the movable plate is pressed to a fixed contact point by the distal end of the thermal responsive element.
Concerning a structure of a relay, Japanese Patent Application Publication No. 05-81983 discloses a system for connecting a contact point with a movable plate mounting portion through a flexible conductive wire in order to prevent the movable plate from being fused when a short-circuit current flows. Furthermore, Japanese Patent Application Publication No. 2004-133568 discloses a configuration of a power switch including a resistor and a contact point both connected in series with a bimetal, in which both ends of the bimetal and the resistor are short-circuited with another switch. As a result, when the bimetal was heated by a current and then inverted, the first switch is closed.